Syringe nozzle



Dec. 9, 1958 Y 'r. H. GEWECKE SYRINGE NOZZLE Filed Dec. 4, 195a THEODORE H. GEwEcKE INVENTOR.

BY 2M United States Patent SYRINGE NOZZLE Theodore H. Gewecke, Glenview, Ill., assignor to Baxter Laboratories, Inc.

Application December 4, 1956, Serial No. 626,263

3 Claims. (Cl. 128227) This invention relates to a syringe nozzle, and more particularly to a self-lubricating syringe nozzle.

It is an object of my invention to provide a self-lubricated syringe nozzle. Another object of my invention is to provide a syringe nozzle constructed of an extrudable, thermoplastic material having admixed therewith a quantity of mineral oil sufiicient to continually exude. Still another object of my invention is to provide a molded thermoplastic device having a self-lubricated outer surface. Other objects and advantages of my invention will appear as this specification proceeds.

My invention will be explained in conjunction with the attached drawing which is a perspective view of a disposable enema bag equipped with the self-lubricating nozzle of my invention.

Referring now to the drawing, the numeral indicates generally a disposable enema bag constructed of a flexible, transparent plastic material such as polyvinyl chloride. The liquid containing portion of the bag 10 is a rectangular, closed envelope designated 11. Envelope 11 is filled with a suitable enema fluid such as a phosphate solution. Envelope 11 is provided with a length of flexible plastic tubing 12 communicating with the interior and secured to the bag as by heat-sealing. Outflow of fluid from envelope 11 through tubing 12 is controlled by ball check valve 13 mounted in tubing 12 inward of envelope 11.

The unsecured end of tubing 12 is provided with a nozzle 14 which is constructed in accordance with the teaching of my invention. When not in use, nozzle 14 is carried by a slot or recess 15 in envelope 11.

To construct nozzle 14, I mix a resinous material such as polyvinyl chloride with a suitable quantity of mineral oil, heat the ingredients while they are being mixed, extrude the mixture, pelletize the extruded rod and then employ an injection molding machine to form nozzle 14.

In the past it has been a recognized procedure to add a slight quantity of mineral oil to a resinous mixture to provide a processing lubricant during extrusion and molding. By adding a substantially greater quantity, I have found that the mineral oil will provide a lubricant for the outer surface of the molded device and continue to do so irrespective of continued removal of the surface lubricant as by wiping.

A formula I employ for construction of the self-lubrieating nozzle of my invention is set forth below in Table I:

Table 1 Material Parts iPercent Range Polyvinyl chloride resin such as Bakelite YS 57 100 Dioctyl phthalate (Other types of plasticizers such as didecyl adipate, etc. could be used) 46 26. 5 30-60 Orgauo tin stabilizer such as Advance Solvent and Chemical Company #52. 31 2 0-5 Organo tin stabilizer such as Advance Solvent and Chemical Company #50 LT 2 1. 2 0-5 Mineral oil such as Ramol 350 made by Sherwood Refining C0 16 9. 2 10-20 Calcium stearate lubricant such as Witco Chemical Co. Stayrite 25. 1 0. 6 0-4 Inorganic filler such as C. K. Williams Co. Super White Silica 6 3. 5 0-50 Carbon Black such as Darco made by Can be varied or other Atlas Powder 0.006 pigments or dyes could Blue Pigment such as Cyan Blue be used to obtain any Toner made by American Cyanadesired color. Also, no mid Company 0.003 coloring matter could be used and a natural color obtained.

The foregoing formula is set forth in the first case on the basis of parts by weight of the various ingredients employed. In the field of molded plastics a formula is conventionally written on the basis of 100 parts of T6811].

It is to be noted that the range of mineral oil employed, 10 to 20 parts or about 9 to 18%, is substantially greater than that previously employed as a processing lubricant. For a processing lubricant in the same composition, mineral oil would only be added from about one-quarter part to two parts based on 100 parts of the resin material. To provide a self-lubricant, it is necessary that a quantity sufiicient be incorporated that the mineral oil will bleed out considerably upon standing. About 10 parts is required to give a noticeable bleeding and this I consider a minimum quantity usable for the purpose of providing a self-lubricated outer surface in an injectable thermoplastic device. The upper limit of the amount of mineral oil to be incorporated is set by the maximum amount of oil that can be incorporated into the formula and still not have the mixture so slippery that it will not mix. I find this to be about 20 parts of mineral oil with 100 parts by weight of resin.

The actual manufacturing procedure for making the self-lubricated syringe nozzle 14 described above involves the following steps: First the resin is dumped in a blender such as a J. H. Day ribbon blender. Next all the ingredients except mineral oil are mixed in a kettle which is heated to about to 200 F. These ingredients are then pumped or slowly poured into the blender while mixing is continued. The ingredients in the blender are now continued to be heated to about 180-200 F. While mixing is continued, the requisite quantity of mineral oil is added and the temperature of the mixed ingredients is reduced to about 100-120 F.

The mixture achieved above is then conveyed to a single-screw extruder and the oily blend is fed into the extruder by alternately filling the hopper opening with blend and then forcing it in with a wooden plunger. The slipperiness of the blend prevents its being fed into the extruder in the conventional manner utilized with Patented Dec. 9, a

dry granular mixes. The plastic issues 7 from the extruder through a single opening in the form of a rod. However, multiple openings could be used. The rod is then pelletized in a Ball and Jewell grinder and the pellets then conveyed to an injection molding machine where the pellets are molded into the above-described syringe nozzles.

The foregoing detailed description has been given for clearness of understanding only and no unnecessa limitations are to be inferred therefrom.

I claim: 1. A nozzle springe constructed of an extrudable thermoplastic material having incorporated therein a sufficient quantity of mineral oil to continually maintain the outer surface of said nozzle coated with a lubricating film of mineral oil.

2. A nozzle syringe constructed of an extrudable, thermoplastic resin and mineral oil whereby the mineral oil maintains the outer surface of said nozzle'coated with a lubricating film.

3. A molded thermoplastic syringe nozzle wherein the composition of said nozzle comprises about 10 to 20 parts by weight of mineral oil and about 100 parts by weight of a thermoplastic resin whereby said nozzle has a self-lubricated outer surface.

References Cited in the file of this patent UNITED STATES PATENTS 

